I worked with someone on a G4 MYSTIC model. Trying to get OS 9 working. OS X was already working fine. It had a 1.2ghz CPU. It would hang early in Mac OS 9.2.2 startup. Switching to stock 450mhz CPU fixed hanging. NOT SURE WHY! The 1.2ghz ended up working fine (so far) with a different system folder. Why so? In what way would software corruption affect only some clock speed?
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mystic glitch question
- Thread starter chet david
- Start date
to clarify, it would consistently hang with the 1.2ghz CPU. would consistently NOT hang with the 450. It took many tries and attempts to get a working 9.2.2. install with the 1.2ghz.
Have you ever played a really old Mac game on a newer Mac? They are sometimes inadvertently programmed in such a way that relies on the speed of the CPU, so they run WAY too fast to even play on the newer Mac. Old versions of Brickles are like that.
It could be that part of the system loads too fast because of the speedy CPU and is expecting something else to have already taken place, maybe some piece of hardware to be initialized. In all circumstances during development, it may not have been possible for the CPU to outrun the offending issue, and now that it can, it just crashes when it happens.
Another possibility is defective hardware. Classic Mac OS utilizes hardware differently than OS X. For example, if you had a sketchy Rage Pro video card, Mac OS X would not use the 3D acceleration of that card and OS 9 would, thus causing crashing only in OS 9. There could be a special function of the CPU, some sort of extra boost that OS X does not support, and similarly when utilized in OS 9, produces the crash.
It could be that part of the system loads too fast because of the speedy CPU and is expecting something else to have already taken place, maybe some piece of hardware to be initialized. In all circumstances during development, it may not have been possible for the CPU to outrun the offending issue, and now that it can, it just crashes when it happens.
Another possibility is defective hardware. Classic Mac OS utilizes hardware differently than OS X. For example, if you had a sketchy Rage Pro video card, Mac OS X would not use the 3D acceleration of that card and OS 9 would, thus causing crashing only in OS 9. There could be a special function of the CPU, some sort of extra boost that OS X does not support, and similarly when utilized in OS 9, produces the crash.
That is funny considering that they shipped 1.25ghz MDDs running OS 9.
Could this be cache related? If I recall these aftermarket upgrades would need third party extensions or drivers to utilise the L2 caches on the processor. Now if the system folder in question had an extension that accessed the processor or hardware on the processor daughtercard directly, this could work fine with the 450MHz stock processor but present anomalies with the 1.2GHz aftermarket processor.
Following so far? Awesome.
This would explain why a different system folder would run fine with the 1.2GHz card, also why Mac OS X would run fine on the same processor, but one OS 9 system folder wouldn't. It's extension related, it just so happens that in this scenario it doesn't like something that is present, or not present, on the upgraded CPU.
Best I could come up with off the top of my head anyway.
Following so far? Awesome.
This would explain why a different system folder would run fine with the 1.2GHz card, also why Mac OS X would run fine on the same processor, but one OS 9 system folder wouldn't. It's extension related, it just so happens that in this scenario it doesn't like something that is present, or not present, on the upgraded CPU.
Best I could come up with off the top of my head anyway.
Did you try booting with Extensions off with the "non-working" System Folder?
I have just such a dual 1.25 GHz MDD G4. They did not ship Mystic G4s that were that fast though. There may be something on the logic board that does not initialize fast enough, so the faster processor outruns it in certain situations. For example, FireWire may take a while to initialize and Mac OS 9 could try to load a driver before it's done initializing. That's what I was talking about regarding how fast the processor is.
Aftermarket CPUs normally work without issue. I know a Sewde who has a 1.2GHz sonnet in his G4 and uses OS9 just fine.(it is mystic too iirc.) I have also never had an issue running 9 on my sawtooth or digital audio with my 1GHz card installed...but my current gfx card never had support and my SATA card cannot boot 9 at all.
I used a 9.2.2 "G4" disc though, but I have also used a retail 9.2.1 disc too unless I am mistaken.
I used a 9.2.2 "G4" disc though, but I have also used a retail 9.2.1 disc too unless I am mistaken.
I think it have may been extension incompatible.
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